arch/arm/plat-omap/common.c

   1 /*
   2  * linux/arch/arm/plat-omap/common.c
   3  *
   4  * Code common to all OMAP machines.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/delay.h>
  14 #include <linux/pm.h>
  15 #include <linux/console.h>
  16 #include <linux/serial.h>
  17 #include <linux/tty.h>
  18 #include <linux/serial_8250.h>
  19 #include <linux/serial_reg.h>
  20 #include <linux/clk.h>
  21
  22 #include <asm/hardware.h>
  23 #include <asm/system.h>
  24 #include <asm/pgtable.h>
  25 #include <asm/mach/map.h>
  26 #include <asm/io.h>
  27 #include <asm/setup.h>
  28
  29 #include <asm/arch/board.h>
  30 #include <asm/arch/mux.h>
  31 #include <asm/arch/fpga.h>
  32
  33 #include <asm/arch/clock.h>
  34
  35 #define NO_LENGTH_CHECK 0xffffffff
  36
  37 unsigned char omap_bootloader_tag[512];
  38 int omap_bootloader_tag_len;
  39
  40 struct omap_board_config_kernel *omap_board_config;
  41 int omap_board_config_size;
  42
  43 static const void *get_config(u16 tag, size_t len, int skip, size_t *len_out)
  44 {
  45         struct omap_board_config_kernel *kinfo = NULL;
  46         int i;
  47
  48 #ifdef CONFIG_OMAP_BOOT_TAG
  49         struct omap_board_config_entry *info = NULL;
  50
  51         if (omap_bootloader_tag_len > 4)
  52                 info = (struct omap_board_config_entry *) omap_bootloader_tag;
  53         while (info != NULL) {
  54                 u8 *next;
  55
  56                 if (info->tag == tag) {
  57                         if (skip == 0)
  58                                 break;
  59                         skip--;
  60                 }
  61
  62                 if ((info->len & 0x03) != 0) {
  63                         /* We bail out to avoid an alignment fault */
  64                         printk(KERN_ERR "OMAP peripheral config: Length (%d) not word-aligned (tag %04x)\n",
  65                                info->len, info->tag);
  66                         return NULL;
  67                 }
  68                 next = (u8 *) info + sizeof(*info) + info->len;
  69                 if (next >= omap_bootloader_tag + omap_bootloader_tag_len)
  70                         info = NULL;
  71                 else
  72                         info = (struct omap_board_config_entry *) next;
  73         }
  74         if (info != NULL) {
  75                 /* Check the length as a lame attempt to check for
  76                  * binary inconsistency. */
  77                 if (len != NO_LENGTH_CHECK) {
  78                         /* Word-align len */
  79                         if (len & 0x03)
  80                                 len = (len + 3) & ~0x03;
  81                         if (info->len != len) {
  82                                 printk(KERN_ERR "OMAP peripheral config: Length mismatch with tag %x (want %d, got %d)\n",
  83                                        tag, len, info->len);
  84                                 return NULL;
  85                         }
  86                 }
  87                 if (len_out != NULL)
  88                         *len_out = info->len;
  89                 return info->data;
  90         }
  91 #endif
  92         /* Try to find the config from the board-specific structures
  93          * in the kernel. */
  94         for (i = 0; i < omap_board_config_size; i++) {
  95                 if (omap_board_config[i].tag == tag) {
  96                         if (skip == 0) {
  97                                 kinfo = &omap_board_config[i];
  98                                 break;
  99                         } else {
 100                                 skip--;
 101                         }
 102                 }
 103         }
 104         if (kinfo == NULL)
 105                 return NULL;
 106         return kinfo->data;
 107 }
 108
 109 const void *__omap_get_config(u16 tag, size_t len, int nr)
 110 {
 111         return get_config(tag, len, nr, NULL);
 112 }
 113 EXPORT_SYMBOL(__omap_get_config);
 114
 115 const void *omap_get_var_config(u16 tag, size_t *len)
 116 {
 117         return get_config(tag, NO_LENGTH_CHECK, 0, len);
 118 }
 119 EXPORT_SYMBOL(omap_get_var_config);
 120
 121 static int __init omap_add_serial_console(void)
 122 {
 123         const struct omap_serial_console_config *con_info;
 124         const struct omap_uart_config *uart_info;
 125         static char speed[11], *opt = NULL;
 126         int line, i, uart_idx;
 127
 128         uart_info = omap_get_config(OMAP_TAG_UART, struct omap_uart_config);
 129         con_info = omap_get_config(OMAP_TAG_SERIAL_CONSOLE,
 130                                         struct omap_serial_console_config);
 131         if (uart_info == NULL || con_info == NULL)
 132                 return 0;
 133
 134         if (con_info->console_uart == 0)
 135                 return 0;
 136
 137         if (con_info->console_speed) {
 138                 snprintf(speed, sizeof(speed), "%u", con_info->console_speed);
 139                 opt = speed;
 140         }
 141
 142         uart_idx = con_info->console_uart - 1;
 143         if (uart_idx >= OMAP_MAX_NR_PORTS) {
 144                 printk(KERN_INFO "Console: external UART#%d. "
 145                         "Not adding it as console this time.\n",
 146                         uart_idx + 1);
 147                 return 0;
 148         }
 149         if (!(uart_info->enabled_uarts & (1 << uart_idx))) {
 150                 printk(KERN_ERR "Console: Selected UART#%d is "
 151                         "not enabled for this platform\n",
 152                         uart_idx + 1);
 153                 return -1;
 154         }
 155         line = 0;
 156         for (i = 0; i < uart_idx; i++) {
 157                 if (uart_info->enabled_uarts & (1 << i))
 158                         line++;
 159         }
 160         return add_preferred_console("ttyS", line, opt);
 161 }
 162 console_initcall(omap_add_serial_console);
 163
 164
 165 /*
 166  * 32KHz clocksource ... always available, on pretty most chips except
 167  * OMAP 730 and 1510.  Other timers could be used as clocksources, with
 168  * higher resolution in free-running counter modes (e.g. 12 MHz xtal),
 169  * but systems won't necessarily want to spend resources that way.
 170  */
 171
 172 #if defined(CONFIG_ARCH_OMAP16XX)
 173 #define TIMER_32K_SYNCHRONIZED          0xfffbc410
 174 #elif defined(CONFIG_ARCH_OMAP24XX)
 175 #define TIMER_32K_SYNCHRONIZED          (OMAP24XX_32KSYNCT_BASE + 0x10)
 176 #endif
 177
 178 #ifdef  TIMER_32K_SYNCHRONIZED
 179
 180 #include <linux/clocksource.h>
 181
 182 static cycle_t omap_32k_read(void)
 183 {
 184         return omap_readl(TIMER_32K_SYNCHRONIZED);
 185 }
 186
 187 static struct clocksource clocksource_32k = {
 188         .name           = "32k_counter",
 189         .rating         = 250,
 190         .read           = omap_32k_read,
 191         .mask           = CLOCKSOURCE_MASK(32),
 192         .shift          = 10,
 193         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 194 };
 195
 196 static int __init omap_init_clocksource_32k(void)
 197 {
 198         static char err[] __initdata = KERN_ERR
 199                         "%s: can't register clocksource!\n";
 200
 201         if (cpu_is_omap16xx() || cpu_is_omap24xx()) {
 202                 clocksource_32k.mult = clocksource_hz2mult(32768,
 203                                             clocksource_32k.shift);
 204
 205                 if (clocksource_register(&clocksource_32k))
 206                         printk(err, clocksource_32k.name);
 207         }
 208         return 0;
 209 }
 210 arch_initcall(omap_init_clocksource_32k);
 211
 212 #endif  /* TIMER_32K_SYNCHRONIZED */